Math 8R
posted by Laruen .
why is every whole number an integer?

That's the definition of integer.
http://www.mathsisfun.com/wholenumbers.html 
Because integers are negative or positive whole numbers they can never be rational or irrational numbers.

Thanks you Ms. Sue for the info. and thank you Sonya for including that! :)

You're welcome, Laruen.

Sonya  integers can be rational numbers